Tagged Questions
3
votes
1answer
229 views
Measure hard-disk read(), write() speed without caching in QNX 6.5
I am working on QNX 6.5 Operating system. QNX 6.5 supports POSIX APIs. I am trying to build an application which is used to evaluate performance of hard-disks. My application will read/write/read ...
4
votes
4answers
163 views
If I have an SSD and a hard disk in a system, can the SSD act as cache for the hard disk?
Say I have some partitions; one on a SATA drive and one on an SSD. I want to create a "virtual" hybrid disk. Is this possible?
11
votes
1answer
951 views
Is disabling barriers for ext4 safe on a laptop with battery?
The manual page says about the barrier option for ext4:
Write barriers enforce proper on-disk ordering of journal commits, making volatile disk write caches safe to use, at some performance ...
5
votes
2answers
823 views
How to time grep commands accurately?
I want to compare the speed of these two commands:
grep pattern1 files*
grep pattern2 files*
Unfortunately, the first grep reads much of files* into memory
buffers, so the second grep runs ...
5
votes
1answer
278 views
Why doesn't dm-crypt handle write barriers properly?
One of the well-known properties of dm-crypt is that it does not handle write barriers properly and hence it requires turning off on-drive write cache to prevent corruption of filesystems. As far as I ...
